Improvement in link-motions for steam-engines



F. FISCHER.

LINED/LOTION FOR STEAM-ENGINES.

Patented June 19, 1877.

Y ATTORNEY I mvmwon:

N.FET'ER8, PPIOTO-LITHOGRAPHER, WASHINGTON, D C

UNITED STATES PATENT CFFICE.

FREDERICK FISCHER, OF NEW YORK, N. Y.

IMPROVEMENT lhl LINK-MOTIONS FOR STEAM-ENGINES.

Specification forming part of Letters Patent No. 192,158: dated June 19, 1877; application filed May 28, 1877.

valve may be modified in such a manner as to move at greater speed when closing and opening the ports, so that the steam-engine may be Worked more effectively for expansion by retaining the steam longer, and also facilitating the entrance and exhaust of the same.

The invention consists of the combination of the slide-pin of the link with a second slide-pin of the slotted rocker-arm, and with a swinging crank-pin, connecting the slidepms.

In the drawing, A represents the driving axle or shaft, which is connected in the customary manner by the eccentrics B C and rods B C, with the link D, that is raised or lowered on the slide-pin D, so as to work the slide-valve with full or partial strokes, or reversing the same, as required. By working the engine with short strokes, the steam is cut off and worked expansively, so as to produce a greater effect.

For the purpose of utilizing still more the expansive force of the steam, the rocker-arm E is slotted at the lower end, and provided with a second slide-pin, E, that moves there- I in, being connected with the slide-pin of the link D by the pivot-pin of a swinging crank-- arm, F.

This connection of the link slide-pin with the slotted rocker-arm results in a modified motion of the slide-valve, imparting to the same an accelerated speed when opening the entrance-port, so as to quickly open the port to its full extent, for the more favorable admission of the steam, while retaining the valve longer over the opposite port, and opening then the same with the same accelerated speed for exhaustion.

This results in the quicker entrance and exhaust of the steam to and from the cylinder, and in the more effective working of the same for expansion.

The travel of the valves is improved by the compound motion obtained by the joint action of the motions of the link, and of the slide-pins and crank-arm on the slotted rockerarm.

The crank-arm F will affect both link and rocker-arm in forward as well as backward motion; but in going forward I derive a gain from link and rocker-arm, while in going backward the gain in link is diminished, but not sufficiently to neutralize the gain in rocker-arm E.

At full stroke the crank-arm F describes an arc of about fifty degrees, raising the linkblocks in the link, as well as rocker-arm, about one and one-fourth inch, the. highest point being reached when the valve is in the center and the steam-ports covered equally on both sides. I

The crank-arm serves, also, to bring the link-blocks in the link and rocker-arm back,

to the same line when the stroke is beginning or finishing. The link-block is raised upward from the center, and that in rockerarm brought nearer to center on the forward movement, so as to increase the speed of valve.

On the backing motion I lose the gain on link to a great extent; but this is unimportant, as high rates of speed are not used in backing.

My valve is behind time both on the forward and backward movement in the first half of its travel; but as soon as it reaches the center it takes on accelerated speed, thus producing a stronger pressure on the piston, and enabling me, when going at a high rate of speed, to work the valves at a much shorter stroke, and, of course, with more'expansion, thus saving much steam.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- The combination of the link D, having slidepin D, slotted rocker-arm E, having slidepin E, and swinging crank-arm F, connecting both slide-pins by pivot-pin, substantially in the manner and for the purpose specified.

. FREDERICK FISCHER.

Witnesses: I

PAUL GOEPEIJ, ALEX. F. ROBERTS. 

